SRST Alias command final destination

[James Hawkins]

Hi,

I am running SRST on a 2811 router  with IOS 12.4(7).

I have alias and call forward no answer commands configured as shown below.

alias 1 3000 to 3001 cfw 3000 timeout 10

alias 2 3000 to 3002 cfw 3000 timeout 10

alias 3 3000 to 3003 cfw 3000 timeout 10

alias 4 3000 to 3004 cfw 3000 timeout 10

alias 5 3000 to 3005 cfw 3000 timeout 10

call-forward noan 90123456789 timeout 10

What I want to happen is for incomin calls to 3000 to ring on extensions 3001, 3002, 3003, 3004 and 3005 and then be forwarded to the PSTN number

90123456789

The config above does not work as the call-forward noan command only seems to work for calls direct to ephone-dn's rather than calls matched by the alias command.

Does anyone know if this is possible with SRST?

I know that this could be done using CME-as-SRST and I will go that way if I have to but I would first like to be sure that this cannot be done using basic SRST.

Thanks

[Chris Deren]

You need to add:

alias 6 3000 to 90123456789

HTH,

Chris

[James Hawkins]

HI Chris,

That is what I initially thought but it does not work.

The Command Reference states the following with respect to the "to" destination.

Alternate telephone number to route incoming calls to match the number

pattern. The alternate number has to be a specific extension that belongs to

an IP phone that is actively registered on the Cisco Unified SRST router.

The alternate telephone number can be used in multiple alias commands.

[James Hawkins]

I have found an article written by Bill Bell which has some useful information abou hairpinning calls to the PSTN under SRST.

http://www.netcraftsmen.net/blogs/entry/redirecting-called-numbers-in-srst-the-alias-command-and-hairpin-methods.html

Bill has a good solution for doing this but does not consider my specific use case of going through a few alias commands and then hairpinning the call.

Any ideas???

[James Hawkins]

Have done some testing and the config below seems to work:

alias 1 3000 to 3001 cfw 3000 timeout 10

alias 2 3000 to 3002 cfw 3000 timeout 10

alias 3 3000 to 3003 cfw 3000 timeout 10

alias 4 3000 to 3004 cfw 3000 timeout 10

alias 5 3000 to 3005 cfw  90123456789

The problem I have now is that if one of the extensions 30001, 3002, 30003, 3004 or 3005 is not available the call fails.

These numbers are allocated to Extension Mobility profiles and the users often log out when away from the office so this is not that unusual.

[Amine Nouasri]

How about using a Hunt Group when phones are in SRST? The config should be something like:

voice hunt-group 1 seq

final 90123456789

list 3001,3002,3003, 3004, 3005

timeout 10

pilot 3099

call-manager-fallback

alias 1 3000 to 3099

I am curious about if this would work. Let us know if you get a chance to test this config out.

Please rate helpful answers!

[Chris Deren]

I don't think you can use hint group unless you use CME as SRST.
The behavior you are experiencing is expected when one if the phones is unavailable.
If you need very robust SRST consider enhanced SRST or CME as SRST.

Chris

Sent from Cisco Technical Support iPhone App

[Carlo Poggiarelli]

Hunt group in SRTS mode are not configurable and , as Chris suggested (+5P)  CME as SRST is the way to go to maintain more CUCM configured features than in SRST.

HTH

Regards

Carlo

Please rate all helpful posts

"The more you help the more you learn"

[James Hawkins]

Thanks for the responses.

Chris is this phone behaviour really what is expected? - I guess it must be because it matches what I have seen but it is pretty lame.

I was considering a shonky workaround where I would configure the users normal DN on the second line of the logged out phone (but with a different partition and CSS to stop unauthorised calls) which would mean the extensions would be available for the alias command under SRST regardless of whether the user is logged in or not.

I am cringing a bit thinking of all the SRST configs I have done which would break if the phone in the first alias command was unplugged. I always assumed the router would just try the next alias.

Guess I might have to look at CME as SRST but that has it's own issues. You have to add the ephone-dn's statically before they can be used in hunt groups don't you?

Has anyone used Enhanced SRST? - is it worth the extra cost of the UMG?

[Chris Deren]

Yes, with alias command if the phone is not registered it does not move down the list.

I have deployed CME as SRST with B-ACD, etc at many customers, but never worked on E-SRST as most customers are not willing to pay extra for it.

HTH,

Chris

[Amine Nouasri]

Hunt Groups might not be the best option here but they are definitely configurable. I just verified it in IOS ipvoice 12.4.

And I have used and tested Hunt Groups when phones in SRST mode in IOS 15.1 succesfully.